[4.1.2] injectEvent problem under IE

REQUIRED INFORMATION

Ext version tested:

Ext 4.1.2

Browser versions tested against:

IE9

DOCTYPE tested against:

<!DOCTYPE html>

Description:

If use iframe with ExtJS then 'injectEvent' method of EventObject in parent page causes few issues. If iframe inside a window then window dragging is interrupted. Also, if open window with iframe, close and open again then an error occurs in handleSingleEvent of EventManager. The issue doesn't occur in 4.1.1

Steps to reproduce the problem:

Open the sample from above test case (it contains from two files: main page and page is loaded inside iframe)

Click on the button to show a window

Try to drag the window

Notice that dragging performance is bad (in 4.1.1 the dragging is smooth)